Dead iMac, Black Screen, No Chime, No nothing.

I am working on an Intel iMac (Early 2006?). I assume this because of what I've been told, also, its white, and has no LEDs-- Its dead as a door nail. I've hooked it up to other monitors, I've tried booting it in Target Disk Mode to another computer. I've switched out power cords, tried different outlets and pulled the RAM out trying multiple scenarios. As far as I can tell the next step is to crack it open. Should I be targeting the PSU (Power Supply)? Not sure how to test these, could also be Video Card or Motherboard I'm told, maybe with a dead computer though it can be anything.

I don't hold much hope for a cheap easy fix. There may be diagnostic lights to the right of the RAM slots. Open it up and try to start and see if you get any lights. You should get #1 green even if the power supply is gone.

I don't mind the cheap pain in the butt fix, its the expensive pain in the butt fix I'd like to avoid. When you say to the right of RAM slots-- Is that looking at it straight on as if I was using it normally, or looking at the bottom of the iMac straight on to the RAM slots? I can't seem to find them, they should be labeled 1,2,3 & 4 correct?

Some of these early ones didn't have the leds. Most that I've seen are covered up by a small piece of black tape extending up from the bottom of the logic board to the right of the RAM slots as when normally operating it. Take it off.

Got it (I think) I'll pull the tape off tomorrow-- while i'm thinking about it. If someone installed the wrong memory in this iMac could that ruin it? would it run with the wrong memory? There are 2 1GBs of RAM in the RAM slots currently. If I pull them both out does the computer have built-in RAM also that would permit it to run? Maybe I'll swap the RAM out with another unit and test that theory.

It's called a SMC or PMU reset. A power management reset. On this machine it may be a PRAM battery failure. With your internet disconnected for a day see if you loss the correct date and time after powering off for a while. If so replace the PRAM battery.

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